Soft tissue repair grafts and processes for preparing and using same

ABSTRACT

Soft tissue repair grafts are provided for supporting, covering, and/or retaining an implant positioned in the body of a subject. The grafts are particularly suitable for use for pre-pectoral breast reconstruction with a breast implant or tissue expander. The grafts include positional notches for more accurate positioning in a subject. The grafts also include at least one cuff element which is folded to form a reinforced folded edge for suturing the graft more securely to adjacent tissues than previously known grafts. The grafts also include a plurality of arcuate slots which form a plurality of circular patterns arranged concentrically about a focal point, thereby enabling the grafts to expand without tearing and to conform more closely to the implant and/or adjacent body tissues such as the breast pocket, than previously known grafts. Acellular dermal matrices are particularly suitable for making the soft tissue repair grafts.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/125,435, filed Sep. 7, 2018, now issued as U.S. Pat. No. 10,813,743on Oct. 27, 2020, and which is hereby incorporated herein in itsentirety.

FIELD OF THE INVENTION

The present invention relates generally to grafts for soft tissue repairand capable of supporting, covering or retaining an implant positionedin the body of a subject. More particularly, the present inventionrelates to grafts capable of supporting, covering and retaining animplant for breast reconstruction and similar plastic surgeryprocedures, and especially for pre-pectoral breast reconstructionprocedures.

BACKGROUND OF THE INVENTION

Surgical procedures for the repair, reconstruction and modification oftissues, organs, and other body parts of humans and other species arecommon. Such surgical procedures include, for example, the repair ofventral abdominal hernias and other abdominal wall defects, the repairand reconstruction of bone and skin having damage from injury ordisease, and the reconstruction or modification of the breast, nose,buttocks and other organs and body parts to repair damage from injury ordisease or for aesthetic reasons.

These repair, reconstruction and modification procedures often involvethe use of grafts which serve to replace, restore or supplement thestructure or function of the tissues, organs, or other body parts beingtreated. In some cases, grafts are used to support, cover and/or retainone or more other devices (e.g., an implant), to achieve the desiredrepair and reconstruction. Grafts may also be used to deliver andadminister therapeutic agents or substances, such as pharmaceuticalcompounds, antibiotics, tissuegenic agents, bioactive substances, etc.

Grafts must generally be biocompatible and not immunogenic. In addition,depending on the particular surgical procedure, differences in the size,shape, flexibility, density, tensile strength, ability to retain orrelease therapeutic agents or substances, ability to support and growcells, and other properties, may be beneficial. For example, materialsinitially having a generally planar or sheet-like configuration, withgood flexibility and tensile strength, have been found useful for makinggrafts to support and retain a breast implant such as that implantedduring breast reconstruction.

Breast reconstruction procedures are sometimes performed to repair andreconstruct a breast from which tissue has been removed, such as bymastectomy to remove cancerous tissue, in which case a breast implantsubstitutes for the removed tissue. Sometimes breast reconstruction isperformed for breast augmentation and the breast implant adds volume toexisting tissue. In any case, the breast implant should enable formationof a natural breast shape.

Materials used to make grafts for breast reconstruction should possessbiomechanical properties including predictable suppleness, flexibilityand uniform pliability sufficient for such grafts to stretch and expandwithout tearing during tissue expansion (i.e., using the breast implantand/or a tissue expander), as well as to conform to both the shape andcontour of the implant and the shape and contour of the breast pocket.The most suitable materials for breast reconstruction and similarplastic surgery procedures should also possess sufficient tensilestrength to preclude suture tear-out, both during implantation andexpansion through the post-operative phase, and allow rapid andefficient cellular ingrowth equally from either side of the graft.

For example, processed dermal tissue, which has been decellularized toreduce immunogenicity, is generally known to possess the aforesaidbiomechanical properties and has been used in breast reconstructionprocedures with some success as grafts for covering, supporting, and/orretaining breast implants. Such acellular dermal matrices (“ADMs”) arecommercially available, including FlexHD Structural® ADM and FlexHDPliable® ADM, both of which are marketed by Musculoskeletal TransplantFoundation (Edison, N.J.), as well as AlloDerm® ADM and AlloDerm® Readyto Use (“RTU”) ADM, both of which are marketed by LifeCell Corporation(Branchburg, N.J.). The ADMs are cut to suitable dimensions and shape toconform to the breast implant and the implant location in the patient.Furthermore, while suitable ADM may be derived from almost any animalhaving skin, ADMs used for breast reconstruction procedures have mostoften been derived from mammals, and especially humans and pigs.

Historically, the first breast reconstruction procedures were performedwith a breast implant simply placed in a breast pocket, such as createdby mastectomy, to replace the excised breast tissue. Unfortunately, thismethod was fraught with problems, mainly related to capsularcontracture, with resulting hardening of the implants and externallyvisible rippling or puckering of the skin and underlying tissue. Thiscapsular contracture was found to be reduced when muscle coverage isadded over the implant. Therefore, to overcome the capsular contractureproblem, the breast implants were then placed under (i.e., behind) thechest muscles, i.e., the pectoralis major and serratus anterior. This,however, resulted in other complications, including a much less naturalshape for the reconstructed breast (due to muscle forces over theimplant) and significantly more discomfort for the patient.

To address the foregoing issues, grafts made from ADM were developed andpositioned to support the breast implant inferiorly (i.e., fromunderneath), which allowed the implant to still be placed under thepectoralis major. It has been shown that use of grafts made of ADM forbreast reconstruction with breast implants decreased capsularcontracture.

A more recently developed technique, known as pre-pectoral breastreconstruction, involves placement of the breast implant in front of thepatient's chest muscles (i.e., pectoralis major), with total anteriorcoverage of the breast implant by an ADM graft instead. Suchpre-pectoral ADM grafts have been cut from an ADM, at the time of thereconstruction procedure, to a size and shape suitable to cover theanterior of the breast implant and thereby support the breast implantwithout the need of pectoralis muscle. The ADM graft extends around thebreast implant and is sutured to the pectoralis major at its peripheraledge to form a three-dimensional structure within which the breastimplant is held. Thus, the shape of the ADM graft is important forachieving close conformance between the ADM graft, implant andsurrounding tissue to reduce patient discomfort and aestheticallyundesirable rippling or puckering. This arrangement provides improvedresults over the technique of placing the breast implant beneath thechest muscle, including a more natural shape for the reconstructedbreast and reducing post-operative patient discomfort, while stillminimizing capsular contracture and the complications caused thereby.

Nonetheless, further improvements to the results achieved bypre-pectoral breast reconstruction are desired, including more precisepositioning of the graft with relation to the nipple, overall breastconfiguration and breast implant, as well as minimizing post-operativesuture tear out, capsular contracture and development of externallyvisible rippling and other aesthetically unattractive, or physicallypainful and/or uncomfortable post-operative features. Accordingly,design modifications to grafts used to cover and support the breastimplants in pre-pectoral breast reconstruction procedures, regardless ofwhether the grafts are made of ADM, have been developed that address theforegoing issues.

SUMMARY OF THE INVENTION

The present invention relates to a graft for soft tissue repair, andmore particularly to a graft configured for use in pre-pectoral breastreconstruction surgical procedures.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to theattached drawings, wherein like structures are referred to by likenumerals and/or letters throughout the several views. The drawings shownare not necessarily to scale, with emphasis instead generally beingplaced upon illustrating the principles of the present invention.

FIG. 1 is a top plan view of an exemplary embodiment of a soft tissuerepair graft;

FIG. 2A is a perspective view of a subject having a breast to bereconstructed;

FIG. 2B is a cross-sectional side view of the subject of FIG. 2A, takenalong the plane P, showing the breast B after reconstruction by apre-pectoral reconstruction technique with a breast implant and a graftaccording to FIG. 1 ;

FIG. 2C is a perspective view of the subject and reconstructed breast ofFIG. 2B, where the skin flap S has been removed to show the chest muscleand implanted graft;

FIG. 3 is a perspective schematic view of a section of human skin andthe various components thereof, from which acellular dermal matrices(ADMs) may be fabricated;

FIG. 4 is perspective schematic view of the section of human skin shownin FIG. 3 , showing the cutting steps performed according to an improvedfabrication process to produce improved ADMs;

FIG. 5 a is a perspective schematic view of a section of human skinshowing where cuts may be made according to a previously knownfabrication process for preparing ADMs useful for making soft tissuerepair grafts as described herein; and

FIG. 5 b is a perspective schematic view of a section of human skinshowing where cuts may be made according to an improved process forpreparing ADMs useful for making soft tissue repair grafts as describedherein.

DETAILED DESCRIPTION OF THE INVENTION

Detailed embodiments of the present invention are disclosed herein. Itshould be understood that the disclosed embodiments are merelyillustrative of the invention which may be embodied in various forms. Inaddition, each of the examples given in connection with the variousembodiments of the invention is intended to be illustrative, and notrestrictive. Further, the figures are not necessarily to scale, and somefeatures may be exaggerated to show details of particular components. Inaddition, any measurements, specifications and the like shown in thefigures are intended to be illustrative, and not restrictive. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as examples for teaching oneskilled in the art to variously employ the present invention.

The term “graft” refers to a biologically compatible material, tissue,or substance which is introduced into the body of a subject, eitherpermanently or temporarily, to replace, improve or supplement thestructure or function of tissue, an organ, or other body feature of thesubject and includes, but is not limited to, those used for theadministration or delivery of a therapeutic agent or substance. In thecase of the grafts described herein which are used in pre-pectoralbreast reconstruction procedures, planar grafts are generally mostsuitable, however, the term “graft” as used herein is not limited onlyto those having planar configurations. Grafts may be integrated into apatient's body after implantation.

Where a graft is made of material obtained from the same individual intowhom it is implanted, it is “autologous.” Where the graft is made ofmaterial obtained from a different individual of the same species thanthe individual into whom it is implanted, it is “allogeneic.” Where thegraft is made of material obtained from an individual of a differentspecies than the individual into whom it is implanted, it is“xenogeneic.” The soft tissue grafts may be autologous, allogeneic orxenogeneic.

The term “implant” means a device or material that replaces a missingbody feature or portion thereof, which may be lost through trauma,disease, or congenital conditions, and is intended to restore the normalfunction(s) of the missing body part. Furthermore, an implant can be anymaterial, device or substance which is introduced into the body of asubject, either permanently or temporarily, to replace, improve orsupplement the structure or function of tissue, an organ, or other bodyfeature of the subject and includes, but is not limited to, those usedfor the administration or delivery of a therapeutic agent or substance.

The term “biocompatible” means that the graft or implant, when implantedin a subject, does not cause adverse effects such as, for examplewithout limitation, toxicity, foreign body reaction, or cellulardisruption.

Grafts for soft tissue repair described herein are suitable forsupporting, covering, retaining, or any combination thereof, an implantpositioned in the body of a subject. More particularly, the soft tissuerepair grafts are capable of being more accurately positioned in asubject and more securely attached to adjacent tissues than previouslyknown grafts. Furthermore, the soft tissue repair grafts are capable ofgreater expansion without tearing during tissue expansion (i.e., usingbreast implant and/or tissue expander), while concurrently conformingmore closely to the shapes and contours of both the implant and adjacentbody tissues, than previously known grafts. The improved ability of thesoft tissue graft to conform closely to the shapes and contours of theimplant and adjacent body tissues is more significant and apparent whenthose contours are more rounded, curved, protruding, or recessed (e.g.,concave, convex, projecting, etc.), such as, without limitation, for abreast, knee joint, elbow joint, chin, fingertip, toe, heel, othersimilar body features, and implants for such body features.

While the aforesaid soft tissue grafts will be described in detailhereinafter as used in surgical procedures for breast reconstruction,their utility is not limited to such surgical procedures. Rather,persons of ordinary skill will recognize that the soft tissue grafts areadvantageous for other surgical procedures as well, particularly thoseinvolving repair, reconstruction or modification of body features suchas those mentioned above and others.

The features of the soft tissue repair grafts that provide the aforesaidimproved characteristics will now be discussed with reference to FIGS.1-2C. More particularly, FIG. 1 is a top plan view of an exemplary softtissue repair graft 10 suitable for use in a surgical procedure such asbreast reconstruction. The soft tissue repair graft 10 has an arcuateperipheral edge 12 and a focal point F which is located generally at ornear the geometric center of the graft 10. An imaginary vertical axis Vpasses through the focal point F. An imaginary horizontal axis H alsopasses through the focal point F, with the vertical and horizontal axesV, H intersecting at the focal point F. In embodiments where the graft10 is intended for use in pre-pectoral breast reconstruction procedures,for example, the focal point F will be positioned at the nipple of thebreast undergoing reconstruction.

As shown in FIG. 1 , the graft 10 has a generally circular or slightlyoval shape. As will be understood by persons of ordinary skill in therelevant art, the graft 10 will have dimensions suitable for thelocation and size of the surgical site with which it is intended foruse. For example, a larger sized graft 10 will be suitable and selectedfor a larger sized breast or breast pocket, and a smaller sized graft 10will be suitable and selected for a smaller breast size. Generally, whenthe graft 10 has a generally oval shape and is intended for use in abreast reconstruction procedure, the vertical axis V will be of greaterlength than the horizontal axis H. More particularly, in someembodiments of grafts for use in pre-pectoral breast reconstruction, theratio of the length (L_(v)) of the vertical axis V to the length (L_(H))of the horizontal axis H may be from about 1.05 to about 1.30, such asfrom about 1.10 to about 1.20, or about 1.15.

Additionally, as shown in FIG. 1 and for purposes described hereinafter,the graft 10 has at least three notches 14, 16, 18 at the peripheraledge 12, including a top notch 14 located where the vertical axis Vmeets the peripheral edge 12 above the focal point F, and first andsecond side notches 16, 18 located where the vertical axis V meets theperipheral edge 12 on opposite sides of the focal point F. Inembodiments of the graft 10 having three notches 14, 16, 18, as shown inFIG. 1 , for example, a user (e.g., surgeon) handling the graft 10 priorto implantation in a subject will be able to readily discern which isthe top notch 14 and, therefore, which way to orient the graft 10 toensure it is positioned properly to align with the shape and anatomy ofthe breast or breast pocket being reconstructed. More particularly, whenthe graft 10 has three notches 14, 16, 18 as described above and shownin FIG. 1 , a user may determine a sequence of the notches 14, 16, 18which extends the shortest overall distance and the notch 14 positionedin the middle of the other two 16, 18 is the top notch 14.

With reference still to FIG. 1 , due to the presence of the notches 14,16, 18, the peripheral edge 12 is discontinuous and a plurality of cuffelements 20, 22, 24 are formed. Each cuff element 20, 22, 24 is foldablealong a respective imaginary arcuate line 26, 28, 30 (see dotted linesin FIG. 1 ) which extends from the base of a respective pair of notcheswhich forms each cuff element 20, 22, 24 to form a folded edge (seefolded edge 32 shown in FIG. 2C). For example, with reference to FIG. 1, one cuff element 20 is foldable along its respective imaginary arcuateline 26 between the notches 14, 16 which form that cuff element 20. Whenall cuff elements 20, 22, 24 are thus folded, a reinforced folded edge32 (see FIG. 2C) extends substantially around the entire graft 10. Whenthus folded, the cuff elements provide a superior ring (i.e., thereinforced folded edge 32) of contact with the muscle M for improvedlong term support of the implant I (see, particularly, FIGS. 2B and 2C).Each cuff element 20, 22, 24 may, for example without limitation, have awidth W, measured from the peripheral edge 12 of the graft 10 (see FIG.1 ), of from about 7 millimeters to about 20 millimeters. In someembodiments, each cuff element 20, 22, 24 has a width of from about 10millimeters to about 20 millimeters, or from about 15 millimeters toabout 20 millimeters, or from about 10 millimeters to about 15millimeters, or even from about 12 millimeters to about 18 millimeters.The width of each cuff element 20, 22, 24 will typically be based on thesize of the breast implant being used, as is readily determinable bypersons of ordinary skill in the relevant art. It should be furthernoted that where the graft 10 has more than one cuff element, they neednot all have the same widths as one another.

In some embodiments (not shown per se), the graft 10 may be symmetrical,such that the vertical and horizontal axes V, H each extend to thefarthest and oppositely positioned points on the reinforced folded edge32 and are substantially perpendicular with one another. In otherembodiments such as that shown in FIG. 1 , the graft 10 may besymmetrical only along the vertical axis V, such that the vertical andhorizontal axes V, H each extend to the farthest and oppositelypositioned points 34, 36, 38, 40, respectively, on the folded edge 32and are perpendicular with one another, but the focal point F is ashorter distance from a bottommost (i.e., inferior) point 36 than from atopmost (i.e., superior) point 34 on the folded edge 32. In someembodiments of the graft 10 suitable for use in pre-pectoral breastreconstruction procedures, the distance between focal point F and thebottommost point 36 is from about 40% to about 50%, such as from about42% to about 48%, or such as about 45%, of the total distance betweenthe topmost point 34 and the bottommost point 36, thus optimizingdistribution of breast volume around the nipple for improved breastshape and aesthetic outcome. In still other embodiments (not shown), thegraft 10 may be asymmetrical, such that the vertical and horizontal axesV, H each extend to the farthest and oppositely positioned points on thefolded edge 32, but are not perpendicular with one another. Embodimentsof the graft 10 which are either symmetrical only about the verticalaxis V or asymmetrical may align more closely with a breast and,therefore, may be more suitable for use in breast reconstructionprocedures. In all embodiments, the focal point F will be located at theintersection of the vertical axis V and horizontal axis H. In fully orpartially symmetrical embodiments of the graft 10 described above, thefocal point F is also positioned at the midpoint of the horizontal axisH.

Although not shown in the figures, as will be recognized by persons ofordinary skill in the relevant art, the graft 10 may have differentquantities of notches and cuff elements. For example without limitation,in some embodiments the graft 10 may not have any notches, in which casethe cuff element may also be entirely absent. Alternatively, as will bedescribed below, in some embodiments of the graft 10 which lack anynotches, there may be a single cuff element which extends at leastpartially, or even entirely, around the periphery of the graft 10 forfolding to form a reinforced edge which would be coextensive with thesingle cuff element. Furthermore, as will also be understood by personsof ordinary skill in the relevant art, the graft 10 may, for examplewithout limitation, include only two notches or even a single notch(such as, but not necessarily, positioned at the topmost (i.e.,superior) point 34 of the graft 10), which could form two cuff elements(by two notches), or a single cuff element or even no cuff element atall (by a single notch). For example, a graft might include one or morenotches which are too shallow or small to form cuff elements wide enoughto be used and beneficial in the manner described above, but the notcheswould still perform the function of providing guidance for properlyorienting the graft during its placement in a breast undergoingreconstruction. Thus, it is possible to produce the respective benefitsof the notches or the cuff elements separately, i.e., even in theabsence of the other feature. All such embodiments are within the scopeof the grafts contemplated and described herein. The configuration ofthree notches 14, 16, 18 and three cuff elements 20, 22, 24 shown in thefigures and described in detail hereinabove provides an efficient andeffective combination of these features to provide the positionalguidance for orientation of the graft 10 by a surgeon duringpre-pectoral breast reconstruction, as well as formation of thereinforced folded edge 32 for securing the graft 10 (and thereby, theimplant I), such as with sutures, in the desired position within thereconstructed breast B.

The graft 10 may include a plurality of arcuate slots or openings 42 a,42 b, 42 c, 42 d, 42 e, 42 f, 42 g at least partially through the graft10, which form a plurality of circular patterns 44, 46, 48 which areconcentric about the focal point F. The concentric, circular pattern ofslots or openings 42, 44, 46, 48 about focal point F allow for expansionof the two dimensional graft 10 to reshape into a three dimensionalstructure which conforms in least in part to the spherical shape of thebreast implant. In some embodiments, at least some of the arcuate slotsor openings 42 a, 42 b, 42 c, 42 d, 42 e, 42 f, 42 g are entirelythrough the graft 10. In preferred embodiments of the graft 10, theslots or openings 42 a, 42 b, 42 c, 42 d, 42 e, 42 f, 42 g are not mereholes or perforations, but rather, each of them 42 a, 42 b, 42 c, 42 d,42 e, 42 f, 42 g is elongated. The length of each individual slot (e.g.,42 a, 42 b, 42 c, 42 d, 42 e, 42 f, 42 g), for example withoutlimitation, is typically from about 5 millimeters and about 15millimeters, with longer slots (e.g., slot 42 a, 42 b) forming the outercircular patterns (e.g., pattern 44) and shorter slots (e.g., slot 42 e)forming inner circular patterns (e.g., pattern 48). Additionally, forexample without limitation, in some embodiments, the distance x (seeFIG. 1 ) between successive slots (end-to-end) (e.g., slots 42 a, 42 b)should be from about 5 millimeters to about 15 millimeters, such asabout 10 millimeters.

Typically, the slots 42 a, 42 b forming the outermost circular pattern44, are not closer than about 1.75 centimeters, such as withoutlimitation, not closer than about 1.25 centimeter, or even about 1.5centimeters, from the imaginary arcuate lines 26, 28, 30, between thenotches 14, 16, 18 (or from the reinforced folded edge 32 of the graft10 after implanting). This placement of the slots 42 a, 42 b of theoutermost circular pattern 44 minimizes the risk of unnecessarilyweakening the tensile strength of the graft 10 during and afterimplantation.

The distance d (see FIG. 1 ) between the slots (e.g., slots 42 b, 42 d)forming adjacent circular patterns (e.g., patterns 44, 46) should befrom about 10 millimeters to about 20 millimeters, such as about 15millimeters. In some exemplary embodiments, for larger sized grafts(such as having a largest diameter of from about 26 to about 22centimeters, such as about 25 centimeters), the distance d between theslots (e.g., slots 42 a, 42 c) forming adjacent circular patterns (e.g.,patterns 44, 46) should be from about 15 millimeters to about 20millimeters. In some exemplary embodiments, for medium or average sizedgrafts (such as having a largest diameter of from about 24 to about 20centimeters, such as about 22 centimeters), the distance d between theslots (e.g., slots 42 a, 42 c) forming adjacent circular patterns (e.g.,patterns 44, 46) should be from about 13 millimeters to about 17millimeters. In some exemplary embodiments, for smaller sized grafts(such as having a largest diameter of from about 18 to about 22centimeters, such as about 20 centimeters), the distance d between theslots (e.g., slots 42 a, 42 c) forming adjacent circular patterns (e.g.,patterns 44, 46) should be from about 10 millimeters to about 15millimeters.

With reference now to FIGS. 2A, 2B and 2C, the use of the soft tissuegraft 10 in connection with pre-pectoral breast reconstruction, and thebenefits provided by the aforesaid features, will now be described.Embodiments of the soft tissue graft 10 intended for use in breastreconstruction procedures are generally implanted such that they atleast partially cover, support and retain a breast implant I within thebreast B of a subject.

FIG. 2A shows a perspective view of a subject having a breast B to bereconstructed. FIG. 2B provides a cross-sectional side view of thesubject of FIG. 2A, taken along the plane P, showing the breast B, afterreconstruction using a pre-pectoral reconstruction technique to implanta breast implant I and an exemplary embodiment of the graft 10. In FIG.2B, the chest muscle M as well as the skin flap S and nipple N of thebreast B are shown, with the graft 10 positioned in front of the chestmuscle M and adjacent to the skin flap S, and the breast implant Ipositioned in a pocket formed between the chest muscle and the graft 10.

One technique for performing pre-pectoral breast reconstruction, forexample where a previous mastectomy procedure has already removed breasttissue and left a pocket between the breast muscle and skin, is to liftthe skin flap S away from the chest muscle M of the breast, fold thecuff elements 20, 22, 24 of a graft 10 to form a reinforced folded edge32 and insert the graft 10 superior to the chest muscle (pectoralismajor) M and anterior and adjacent to the skin flap S of the breast B.The graft 10 is oriented and inserted in the pocket between the chestmuscle M and skin flap S with its top notch 14 vertically aligned abovethe nipple N, and its focal point F directly underlying the nipple N.This cuff allows for some surface area of the graft that is folded underthe implant to come in contact with the muscle and function as an anchorproviding extra support for the graft-implant construct resulting inimproved positioning of the implant long-term, thus counteracting forcesof gravity long-term. Without the cuff, the graft-implant constructwould only be in contact and supported by the breast skin, whichstretches with time.

The graft 10 is affixed to the chest muscle M by suturing along almostthe entire length of the reinforced folded edge 32 from the 4 o'clockposition to the 8 o'clock position along the superior edge [26, 28, 30]and leaving a short portion (for example without limitation, from about4.5 centimeters to about 8.5 centimeters in length) of the folded edge32 unsutured so that a pocket (not shown per se) is formed between thechest muscle M and the graft 10. A breast implant I or otherbiocompatible medical device (e.g., tissue expander) is inserted intothe pocket and the pocket is then closed by suturing the remaining shortportion of the folded edge 32 of the graft 10 to the chest muscle M.Suture failure, sometimes referred to as suture “tear-out,” oftenresults in post-operative complications including, without limitation,the graft 10 and/or breast implant I shifting position relative to thenatural breast B and nipple N, which may cause undesirable cosmeticchanges and pain. The reinforced folded edge 32 formed by folding thecuff elements 20, 22, 24 of the graft 10 provides a location forsuturing the graft 10 to the chest muscle M which reduces the risk ofsuture tear-out and corresponding complications.

Additionally, the reinforced folded edge 32 of the graft also providesan area for tissue ingrowth and stabilization of the pocket beyondsutures. As will be recognized by persons of ordinary skill in therelevant art, and although not specifically shown, even if the graft 10does not include notches 14, 16, 18, a portion of the graph proximatethe peripheral edge 12 may nonetheless be folded against the graft 10,in a single continuous cuff element, to form a reinforced folded edge 32at which the graft 10 may be affixed to the chest muscle M with sutures(or staples, etc.), although there may be some slight puckering orgathering of the continuous cuff element portion of the peripheral edge12. Thus, the notches 14, 16, 18 serve not only as orientation guides asdescribed above, but also minimize puckering and gathering along thefolded edge 32 of the graft 10.

FIG. 2C provides a perspective view of the subject and reconstructedbreast B, where the skin flap S has been removed to render the chestmuscle M and implanted graft 10 visible. FIG. 2C also shows the nipple Nartificially superimposed on the graft 10 to show its location relativeto the graft 10 and its plurality of slots 42 a, 42 b, 42 c, 42 d, 42 e,42 f, 42 g and circular patterns 44, 46, 48. The elongate and arcuateshape of the plurality of slots 42 a, 42 b, 42 c, 42 d, 42 e, 42 f, 42 genables the graft 10 to expand and stretch to a greater extent than ifonly holes or perforations were provided in the graft 10, which allowsthe graft 10 to cover and more closely conform to the shape and contoursof the implant I while avoiding failure (i.e., tearing) of the graft 10itself The circular patterns 44, 46, 48 and concentric arrangement ofthe plurality of slots 42 a, 42 b, 42 c, 42 d, 42 e, 42 f, 42 g aroundthe focal point F further enable the graft 10 to conform more closely tothe shapes and contours of both the breast implant I and the skin flap Sand minimize post-operative complications such as rippling andpuckering.

As already discussed above, the graft 10, as described and shown in thefigures, may include a plurality of both notches 14, 16, 18 and cuffelements 20, 22, 24. However, the graft 10 may instead include one ormore notches, or one or more or cuff elements, or one or more of bothnotches and cuff elements, and the quantities of notches and cuffelements need not be the same. Furthermore, the graft 10 may include aplurality of slots 42 a, 42 b, 42 c, 42 d, 42 e, 42 f, 42 g which arearranged in a plurality of concentric circular patterns 44, 46, 48, asdescribed above, regardless of whether or not the graft 10 includes alsoincludes any notches, slots, or both. In some embodiments, for examplewithout limitation, the graft 10 may include such a plurality of slots42 a, 42 b, 42 c, 42 d, 42 e, 42 f, 42 g, but not have any notches orcuff elements. Although these features may cooperate to provide a grafthaving multiple advantages and improved results as compared to othergrafts without such features, as described above, each of these featuresprovides advantages and improved results independently of the others.

Suitable materials for making the soft tissue grafts 10 described hereininclude various tissues such as, without limitation, amnion, chorion,dermal, duodenum, dura, fascia lata, gastrointestinal, intestinalmucosa, intestinal submucosa, pericardium, peritoneum, placenta, andumbilical cord. The most suitable materials for breast reconstructionand similar plastic surgery procedures will possess sufficient tensilestrength to minimize or avoid suture tear-out, both during implantationand expansion through the post-operative phase, and allow rapid andefficient cellular ingrowth equally from either side of the graft.

While not the only particularly suitable material, acellular dermalmatrices (ADMs) have been known and used to make grafts for soft tissuerepair procedures, including without limitation breast reconstructionand other cosmetic surgical procedures. Such materials are known to havesuitable structural and biomechanical properties including, but notlimited to, predictable suppleness, flexibility, uniform pliabilitysufficient to stretch and expand without tearing during tissue expansion(i.e., using a breast implant and/or tissue expander), and sufficienttensile strength.

The nature of the dermal tissue from which these ADMs are derived isexplained with reference to FIG. 3 , which illustrates themicrostructure of human skin. Human skin is recovered from either liveor deceased donors after receiving consent from the individual donor ordonor's family. As illustrated in FIG. 3 , human skin is made of severallayer-like components, including the outer-most epidermis E, and thedermis D, which lies beneath the epidermis. The hypodermis H (alsoreferred to as the subcutis) lies beneath the dermis D, but is not partof the skin. Rather, the hypodermis H contains adipose and muscletissue. The dermis D itself includes the papillary dermis PD, which liesadjacent the epidermis E, and the reticular dermis RD, which liesbetween the papillary dermis PD and the hypodermis H. Thepapillary-reticular dermis interface PRI, lies between the papillarydermis PD and the reticular dermis RD. The dermis-epidermis junction(“the DEJ”) lies between the papillary dermis PD and epidermis E.

The process for deriving the foregoing ADMs from dermal tissue involvesremoving the epidermis E (e.g., by a chemical process that causes theepidermis to slough off), and thereby exposing the DEJ that was adjacentthe epidermis E. Beneath the DEJ lies the papillary dermis PD, thepapillary-reticular dermal interface PRI, and the reticular dermis RD.The dermal tissue that is recovered for the ADMs may therefore includethe DEJ, papillary dermis PD and at least part of the reticular dermisRD. The recovered dermal tissue is decellularized and asepticallyprocessed to meet sterility testing requirements.

The foregoing ADMs are derived from recovered tissue that includes theentire papillary dermis PD. The microstructure of the papillary dermisPD is not uniform. More particularly, the papillary dermis PD has anupper portion, or side, that was immediately adjacent the DEJ andtherefore closer to the epidermis E (i.e., “the epidermal portion”), anda structurally different lower portion, or side, that was farther fromthe DEJ and epidermis E, and adjacent the deeper reticular dermis RD(i.e., “the dermal portion”). The epidermal portion of the papillarydermis PD contains a more densely-packed collagen matrix than therelatively more open collagen matrix contained in the dermal portion. Assuch, the dermal portion is more porous than the epidermal portion. Thisdual structure is also a property of the foregoing ADMs, and is idealfor repairing ventral abdominal hernias and other abdominal walldefects, as the more densely-packed epidermal portion of the ADM (i.e.,incorporating the epidermal portion of the papillary dermis PD)possesses the tensile strength and stiffness required for suchload-bearing tissue repairs, and the more porous dermal portion of theADM (i.e., incorporating the dermal portion of the papillary dermis PD,as well as at least a portion of the loosely-packed and porousunderlying reticular dermis RD) provides an open collagen structure thatpromotes vascularization, cellular attachment and tissue ingrowth.Nevertheless, this dual structure, which may only be visible on amicroscopic scale, presents concerns about identifying and maintainingthe side orientation of the ADM, i.e., during a surgical procedure.

In an improved fabrication process, an ADM is derived from allograftdermal tissue that is recovered from deeper within the dermis, and istherefore farther from, and not adjacent the epidermis. Recovery ofportions of the dermis D from the skin suitable for making such ADMs maybe accomplished by various techniques and devices, such as, for example,a manual dermatome technique, or dissection with a scalpel. In animproved fabrication process illustrated in FIG. 4 , a first cut 50 ismade into the reticular dermis RD of the skin (e.g., a section of skincut from the entire donor skin) proximate the underlying hypodermis H inorder to remove it from the dermis D. A second cut 52 is then made intothe epidermal portion of the papillary dermis PD containing the densecollagen matrix, as discussed above, in order to remove the epidermis E,the DEJ, and the underlying epidermal portion of the papillary dermisPD. The remaining portion of the dermis D (i.e., the deeper dermalportion of the papillary dermis PD and the reticular dermis RD)constitutes a collagen matrix (“the tissue”) having substantiallyuniform density and porosity.

This remaining portion of the dermis, i.e., the tissue, may then beminimally processed, e.g., according to the process disclosed in U.S.Pat. No. 7,723,108, the disclosure of which is incorporated by referenceherein in its entirety. Alternatively, the tissue may be decellularizedby chemically treating it with saline, detergent, peracetic acid,ethanol and propylene glycol. The tissue may then be washed with sterilewater to remove residual processing chemicals. The resulting disinfectedand acellular tissue (ADM) may be cut into rectangular-shaped sheetssuitable for clinical uses. The tissue sheets may be further treatedwith aqueous ethanol and packaged to provide a hydrated ADM.

The ADM derived using the improved process(es) disclosed above exhibitsproperties that are ideal for its use as a sling in breastreconstruction, and its use in other plastic surgery applications. Useof this improved ADM minimizes adhesions and foreign body reactionswhile promoting vascularization, cellular attachment, and tissueingrowth at the surgical site. Compared to the previously known ADMs(i.e., described above), this improved ADM possesses more uniformtensile properties (i.e., strength, pliability, stretchability andhandling characteristics) that are optimal for its use in breastreconstruction and other plastic surgery applications. This improved ADMalso possesses improved suture retention strength, and elasticity anddeformability that are optimal for its intended use. For example, theimproved elasticity of this improved ADM promotes better expansion ofthe tissue in breast reconstruction. This improved ADM is therefore verystrong and closely mimics the biomechanical properties of the tissuethat it is intended to replace. Further, this improved ADM is resistantto bacterial colonization and non-immunogenic, as a result of thetreatment thereto and decellularization thereof.

FIG. 5 a illustrates a previously known process for fabricating thepreviously known ADMs, including those commercially available under thenames FlexHD® Structural™ ADM, AlloDerm® ADM and AlloDerm® RTU ADM),namely, cutting the lower portion of the dermis and hypodermis(represented by straight line 54), and chemically treating the tissue toremove only the epidermis (represented by uneven line 56) and expose theDEJ.

FIG. 5 b illustrates the improved fabrication process mentionedhereinabove which produces improved ADMs having more uniform density andporosity, namely, the lower portion of the dermis and hypodermis are cut(represented by straight line 50), and then a second cut (represented bystraight line 52) is made deeper into the dermis than the aforementionedchemical treatment used to fabricate previously known ADMs. In oneembodiment of the alternative fabrication process, for example, thesecond cut results in the removal of the epidermis, the DEJ, and theupper, epidermal portion of the papillary dermis. As mentioned above,the substantially uniform density and porosity of the improved ADMsproduced by this alternative fabrication process promotes more rapid andefficient cellular ingrowth equally from either side of the ADM graftsas compared to the previously known ADMs (i.e., the FlexHD Structural®ADM, FlexHD Pliable® ADM, AlloDerm® ADM and AlloDerm® RTU ADM).

It will be understood that the embodiments of the present inventiondescribed hereinabove are merely exemplary and that a person skilled inthe art may make variations and modifications without departing from thespirit and scope of the invention. All such variations and modificationsare intended to be included within the scope of the present invention.

EXAMPLES Example 1: Surgical Placement of an ADM Graft DuringPre-Pectoral Breast Reconstruction

The graft is suitable for use in pre-pectoral breast reconstructionprocedures and:

-   -   is made of ADM;    -   has a vertical axis V and a horizontal axis H, where the ratio        of the length of the vertical axis to the length of the        horizontal axis is 1.15;    -   is symmetrical about its vertical axis;    -   has three notches (i.e., at 9, 12 and 3 o'clock positions on the        peripheral edge of the graft);    -   has three cuff elements formed by the three notches;    -   has a focal point positioned at the midpoint of the horizontal        axis and at a point on the vertical axis which is 45% above the        bottommost point on the peripheral edge of the graft;    -   has a plurality of slits which form a plurality of circular        patterns which are concentric about the focal point.        In use, the foregoing ADM graft is placed and secured within a        reconstructed breast to support a breast implant positioned        anteriorly to the chest muscles of a patient during a        pre-pectoral breast reconstruction procedure. The following        steps are performed:

-   1. Make markings on the breast and draw horizontal and vertical    lines centered around the nipple, mark inframammary fold, medial,    lateral and superior portions of the breast to outline the breast    footprint;

-   2. Prepare the Breast Pocket with hemostasis and irrigation;

-   3. Place pocket defining sutures in the lateral aspect and    inframammary fold;

-   4. Use a breast implant sizer to determine the appropriate implant    volume;

-   5. Mark the medial and lateral borders of the implant sizer in the    breast pocket;

-   6. Mark the superior and midpoint of the breast to define the    position on the breast at which the topmost (superior) point (34) of    the graft, which is proximate the top notch 14, will be anchored

-   7. Triple wash the ADM graft with triple antibiotic solution    alternating with betadine and squeeze excess fluid out of the ADM    graft (a suitable triple antibiotic solution includes a mixture of 1    gram of cefazolin, 80 milligrams of gentamicin, and 50,000    International Units of bacitracin, in 500 milliliters of normal    saline;

-   8. Mark the ADM graft to establish the X (i.e., horizontal H) axis    by connecting the notches at points 38 and 40 and Y (i.e.,    vertical V) axis by drawing a perpendicular line starting at the    superior notch at topmost point 34. Marking of these axes allows for    orientation of the ADM graft by correlating the markings on the ADM    graft to the external markings on the patient's skin, thereby    facilitating symmetrical inset and positioning of the ADM graft into    breast pocket;

-   9. Drape the ADM graft over the implant sizer and mark the edge of    the implant circumferentially on the ADM graft adjusting the folds    (e.g., at imaginary arcuate lines 26, 28, 30 on the graft 10, see    FIG. 1 ) and widths of the cuff elements to the size of the implant;

-   10. Fold the cuff elements (edges) of the ADM graft according to the    markings then carefully place the marked ADM into the prepared    breast pocket without touching the skin;

-   11. Adjust the ADM graft position accordingly by correlating the    external markings of the aforesaid axes;

-   12. Find the superior point of the Y (vertical V) axis at the top of    the pectoralis (Point A, e.g., the a topmost (i.e., superior) point    34 of the ADM graft, see FIGS. 1 and 2C);

-   13. Use a continuous 2-0 Monocryl (a commercially available suture    manufactured and marketed by Ethicon of Cornelia, Ga., USA) to    suture the medial edge of the ADM graft to the muscle from Point (A)    to a Point (B) proximate to or on the inframammary fold, leaving an    opening at the inferior edge of adequate size for insertion of the    implant or tissue expander;

-   14. Use a continuous 2-0 Monocryl to suture the lateral edge of the    ADM to the muscle, again starting from Point (A), and continuing to    a Point (C), which is proximate to or on the inframammary fold and    some distance away from Point (B), thereby leaving an opening    adequate for placement of the implant or tissue expander;

-   15. Inject a pain relief agent (e.g., Exparel commercially available    from Pacira Pharmaceuticals of Parsippany, N.J., USA)    circumferentially to provide an long lasting intercostal block;

-   16. Open the final, permanent breast implant (I) and wash in the    triple antibiotic solution;

-   17. Change gloves and place the permanent breast implant into the    breast pocket utilizing a Keller funnel no touch technique;

-   18. Use a ribbon to protect and retract the implant while    interrupted suture 2-0 Monocryl sutures are placed to close the    aforesaid opening of the breast pocket at the inframammary fold;

-   19. Place two drains at the lateral aspect of the inframammary fold    incision; and

-   20. Suture the incision in three layers using 2-0 Moncryl deeper    interrupted sutures, followed by 3-0 Moncryl dermal and subcuticular    sutures.

The invention claimed is:
 1. A tissue-derived graft for treating a body feature of a patient, wherein the body feature has contours, the tissue-derived graft is planar prior to placement in the patient and comprises: an arcuate peripheral edge defining a generally circular or slightly oval shape with a geometric center; a focal point located at or near the geometric center; a plurality of elongated arcuate slots extending entirely through the graft and forming two or more circular patterns which are spaced apart and concentric about the focal point; wherein when the graft is positioned proximate to or in place of the body feature being treated, the graft expands and reshapes into a three dimensional structure which conforms to the contours of the body feature being treated with minimal tearing of the graft and minimal puckering of the graft or surrounding body tissues.
 2. The graft of claim 1, further comprising at least one notch positioned on the arcuate peripheral edge to provide guidance to a user for properly orienting the graft relative to the body feature being treated.
 3. The graft of claim 2, wherein the at least one notch comprises a plurality of notches, each of which is positioned on the arcuate peripheral edge and which are spaced apart from one another to provide guidance to a user for properly orienting the graft relative to the body feature being treated.
 4. A surgical method for treating a body feature of a patient, wherein the body feature has contours, the surgical method comprising: positioning the graft of claim 1 within the patient proximate to or in place of the body feature being treated, and affixing the graft to surrounding body tissues in a manner which permits expansion and reshaping of the graft into a three dimensional structure which conforms to the contours of the body feature being treated.
 5. The graft of claim 1, wherein the graft is sized and shaped for treating a body feature selected from: a breast, a knee, an elbow, a chin, a fingertip, a toe, a heel, a foot, and buttocks.
 6. The graft of claim 1, further comprising: an imaginary horizontal axis intersecting the arcuate peripheral edge at first and second farthest and oppositely positioned points, passing through the focal point such that the vertical and horizontal axes intersect one another at the focal point, and having a horizontal length measured between the first and second farthest and oppositely positioned points, wherein the vertical length is the same as or greater than the horizontal length; a plurality of notches, each notch being positioned on the arcuate peripheral edge to provide guidance to a user for properly orienting the graft relative to the body feature being treated, the plurality of notches comprising: a first notch positioned at the first farthest and oppositely positioned point; a topmost notch positioned at the topmost point of the graft, wherein when the graft is in a preferred orientation relative to the body feature being treated, the topmost notch will be aligned with a superior point of the body feature; a second notch positioned at the second farthest and oppositely positioned point; a plurality of cuff elements, each of which has a width measured from the arcuate peripheral edge, toward the geometric center, to an imaginary arcuate line on the graft, wherein, when the cuff elements are folded at the imaginary arcuate line, a reinforced folded edge is formed for affixing the graft to surrounding body tissue of the patient, the plurality of cuff elements comprising: a first cuff element defined by and extending between the first and topmost notches; a second cuff element defined by and extending between the topmost and second notches; a third cuff element defined by and extending between the first and second notches.
 7. A surgical method for treating a body feature of a patient, the surgical method comprising: positioning the graft of claim 6 within the patient proximate to or in place of the body feature being treated, and affixing the graft to surrounding body tissues.
 8. The graft of claim 1, further comprising a cuff element extending along at least a portion of the arcuate peripheral edge and having a width measured from the arcuate peripheral edge, toward the geometric center, to an imaginary arcuate line on the graft, wherein when the cuff element is folded at the imaginary arcuate line a reinforced folded edge is formed for affixing the graft to surrounding body tissue of the patient.
 9. The graft of claim 1, further comprising a plurality of notches, each of which is positioned on the arcuate peripheral edge and which are spaced apart from one another to provide guidance to a user for properly orienting the graft relative to the body feature being treated.
 10. The graft of claim 1, wherein the graft is formed from a biocompatible material comprising an acellular dermal matrix which comprises a dermal tissue consisting essentially of a portion of a papillary dermis and at least a portion of a reticular dermis, and essentially lacking an epidermis, a dermis-epidermis junction, a portion of papillary dermis proximate the dermis-epidermis junction and a hypodermis.
 11. A surgical method for treating a body feature of a patient, the surgical method comprising: positioning the graft of claim 1 within the patient proximate to or in place of the body feature being treated, and affixing the graft to surrounding body tissues. 